What is sdf?

Some articles on sdf:

Subwavelength-diameter Optical Fibre - Handling
... Being extremely thin, an SDF is also extremely fragile ... Therefore, an SDF is usually mounted onto a special frame immediately after pulling and is never detached from this frame ... is dust particles which may adsorb to the surface of an SDF ...
List Of Robotech Vehicles - Spaceships - SDF-3 - Mysterious Disappearance
... of the original Robotech series, audiences anticipated the return of the SDF-3, but were left hanging by its mysterious disappearance ... of the returning Robotech Expeditionary Force was taken over by the SDF-4 ... Shadow Chronicles, it was revealed that the SDF-3 had been attempting to test-fire the new Neutron-S missiles ...
List Of Robotech Vehicles - Spaceships - SDF-2
... In the fictional setting of Robotech, the SDF-2 Megalord is the second Super Dimensional flagship of the United Earth Forces that was abruptly ... Limited only to existing footage of the SDF-1, a new SDF-2 is never seen and presumed destroyed with the SDF-1 sometime during the Khyron's attack of New ... The Robotech comic adaptation by Comico depicts the SDF-2 as sitting back to back with SDF-1 in Lake Gloval ...
SDF3
... SDF3, SDF-3, Sdf3, Sdf-3 may represent Spatial data file 3 (SDF3) Stromal cell-derived factor-1 (SDF-1, SDF1, Sdf1) Stromal cell-derived factor-1 alpha (SDF-1a, SDF1a ...